larboard (n.)

"left-hand side of a ship" (to a person on board and facing the bow), 1580s, alteration of Middle English ladde-borde (c. 1300), perhaps literally "the loading side," if this was the side on which goods were loaded onto a ship, from laden "to load" (see lade) + bord "ship's side" (see board (n.2)).

Altered 16c. by influence of starboard, then, to avoid confusion of similar-sounding words, it was largely replaced by the specialized sense of port (n.1). The Old English term for it was bæcbord, literally "back board" (see starboard), a term which remains in the other Germanic tongues.